As a crosslinking agent for room temperature cured silicone rubber, coupling agent for glass fiber and SiO2, a strengthing treatment agent for plastic-layer pressing material.

SiSiB PC5131 reacts very readily with water, SiSiB PC5132 reacts slower with water than SiSiB PC5131.

The most common alkoxy crosslinkers are methoxy or ethoxy silanes due to their high reactivity. The reaction precedes by nucleophilic substitution usually in the presence of acid or base catalysts. Alkoxides react directly with silanols or with water to produce silanols. The newly formed silanols can react with other alkoxides or self-condense to produce a siloxane bond and water. When an acid catalyst is used, protonation of the alkoxysilane increases the reactivity of the leaving group. When a base catalyst is used, deprotonation of the silanol forms a reactive silonate anion. The by-product of the reaction is an alcohol. Common metal catalysts for these reactions are alkoxytitanium derivatives and dibutyltin dicarboxylates.